1. Field of the Invention
This invention relates to electrophotographic apparatus and, more particularly, it relates to the formation of booklets from individual original sheets.
2. Description of the Prior Art
It is, of course, well known that to form a booklet from a series of original document sheets, it is desirable to place the original sheets in a particular order so that the booklet, when assembled, will maintain a logical reading order. For example, given a series of original sheets which are to be read in order from page one through page eight, it is logical to form a booklet which maintains the identical order. If the booklet is formed from sheets of paper carrying four images of the original on each sheet of paper, the booklet copy will contain images of the original which are not in sequential order. That is, the first original page appears on half of one side of the first copy and the second original page appears on half of the other side. The seventh and eighth originals will appear on the other halves of the first sheet of paper. The third and fourth originals will appear on the second sheet along with the fifth and sixth originals.
Commercially available reducing copiers with imaging areas large enough to copy two sheets of paper adjacent to each other and capable of duplexing (copying on both sides) copies from these originals, may be used to manually create booklets. For example, the IBM Series III copier instruction manual ("Series III Copier/Duplicator Model 10 and Model 20 Key Operator Instructions", Form No. S548-0300) describes a method for making booklets (signatures), from 81/2".times.11" originals utilizing the reduction and automatic duplex features of the copier. The operation requires that originals be placed adjacent to each other on the document glass in an order calculated to give the booklet order previously described. Considerable operator involvement is required, because the order of originals is completely determined by the order in which the originals are placed on the document glass. Similarly, as described in operator's instructions 610P2625C (date unknown), the Xerox 7000 Signature Maker requires that different originals be selected from a sequential set of originals for copying in each of two copying passes. In U.S. Pat. No. 4,188,881, filed July 28, 1977, originals are divided by the operator into two stacks which are used in rotation to prepare a master for double-size copy sheets.
The prior art also describes techniques for forming adjacent images from sequentially-fed originals. This technique has the advantage of simplifying the manual operation which would otherwise be required to place two originals next to each other on a document glass. For example, U.S. Pat. No. 4,074,934, filed Feb. 26, 1976, discloses a method of forming an image on one section of a copier's drum and then rotating the drum by a plurality of image spaces before forming an image on another section. However, the patent forms a plurality of images from the same original. U.S. Pat. No. 2,682,193, filed Mar. 10, 1951, discloses the formation of side-by-side images of both the front and back of an original. Neither of the referenced patents relates to the production of booklets by a copier.